Did Blender 2.9 remove sticky option from floor constraint?
This option has been removed in 2019 as indicated here by Sergey Sharybin.

Remove Sticky option from the Floor constraint
This option from the very beginning of its existence needed more work
to make it work correct and this was never done.
This option was working fine during continuous playback, when there
are no skipped frames, but it was failing when AV-sync of framedrop
was enabled. It was never working correct when jumping between frames,
including rendering on a farm which usually does frame-range based
rendering.
With copy-on-write things became even more tricky, since the &quot;stuck&quot;
flag was never preserved between re-evaluations.